IB skill practice

Use Bayes theorem in decision contexts

Use prior probabilities and likelihoods to calculate posterior probabilities.

Paper 1, Paper 2 5 marks Difficulty 5

Use Bayes theorem in decision contexts - interpretation demand

In a regional clinic screening model, \(P(A)=0.24\), \(P(+|A)=0.74\), and \(P(+|A')=0.15\). Find \(P(A|+)\). This version asks for the same mathematical quantity after confirming the method from the context. Enter the requested value and choose the interpretation that matches the result.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.